Grapple



Feb. 27, 1962 J. A. DRAIN ET AL 3,023,044

GRAPPLE Filed April 3, 1956 2 Sheets-Sheet 1 Inventors: JAMS A. DRAIN JOHN ALBERT READ JOHN EDWARD GORDON YMWL Attornzy Feb. 27, 1962 Filed April 3, 1956 FIG. 2

J. A. DRAIN ET AL 3,023,044

GRAPPLE 2 Sheets-Sheet 2 36 g [8 Q' 14a Inventors:

JAMES A. DRAIN JOHN ALBERT READ GORDON 3,023,044 GRAPPLE James A. Drain, Blair, Ontario, and John A. Read and John E. Gordon, Gait, Ontario, Canada, assignors to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 3, 1956, Ser. No. 575,778 3 Claims. (Cl. 29488) This invention relates to a grapple which is moved vertically in removing material such as ore or muck occurring in mining operations, excavating, etc., and in particular to a grapple having novel features of construction which among other things increases the efiiciency of the grapple, avoids the tendency of the grapple to tip when picking up material and greatly reduces breakage of parts during operation.

One disadvantage of the grapple presently employed is that, in order to allow the grapple to effectively dig into the material during the operation of picking up the material, it is necessary for the operator to slacken the cable which supports the grapple and unless that is done the grapple will tend to pull itself out of the material as the tines of the grapple close about the material to be moved. However, the slackening of the cable on which the grapple is carried makes it possible for grapple, when it is dropped on top of the material which is to be picked up, to topple over and thus creates a dangerous hazard to any workman who may be standing in the vicinity thereof. As grapples of the kind described herein are used extensively in mining operations, which in many instances require work to be done in close quarters, the danger to the workmen from the foregoing situation is real.

Another disadvantage of the grapples presently in use is that the piston rod which operates the tines from open to closed position is subjected to great strain when chunks of material, such as large pieces of rock or ore,

become lodged between the tines when they are closing around the material and as this is a frequent occurrence the piston rod is frequently broken.

One of the objects of the present invention is to pro vide a fluid operated grapple which at all times, and particularly during the loading of the grapple, will be held and supported in an upright position by the hoistin cable. This is accomplished by attaching the hoisting cable to the grapple in such a manner that as the tines of the grapple close around the material, the relative length of the cable will be increased by the distance that the grapple, as a unit, digs itself into the material. In other words, one of the objects of the invention is to provide a grapple of the kind described herein with a device which will slacken the cable automatically sufii ciently to allow the grapple to dig into the material to be removed without the intervention of the operator. In the present embodiment of the invention, this is accomplished by providing the piston rod of the motor which aotuates the grapple with an extension which extends through and above the cylinder head a distance equal to the stroke of the reciprocable cylinder and attaching the cable to the top end of the said extension.

Another object of the invention is to connect the tines of the grapple to the lower end of the piston rod by means of a member mounted on the lower end of the piston, said member having universal movement relative to the piston rod to prevent binding of the parts.

The construction and operation of the grapple is set forth in the following specifications and illustrated in the accompanying drawings in which:

FIGURE 1 is a perspective view of the grapple constructed in accordance with the present invention, with States Patent the near tine and link broken away to facilitate illustration.

FIGURE 2 is a vertical axial section of the grapple shown in FIGURE 1.

FIGURE 3 is an enlarged fragmentary view, in perspective, showing the spider assembly mounted on the lower end of the piston rod.

The grapple comprises a fluid cylinder 10 which is reciprocable and having an upper cylinder head '11, a base 12 which provides the lower cylinder head, a piston 13, a piston rod 14 on which the piston is mounted and this piston is contained within the cylinder and remains normally stationary with respect to the cylinder during reciprocation of the latter, said rod being extended through the head 11 and base 12, a spider 15 which is universally mounted on the lower end of the piston rod indicated by the numeral 14b in the manner to be hereinafter described, the spider having pivotally attached thereto six tines 16, each tine being connected to the base 12 by means of a connecting link 17 as hereinafter described. The invention, however, is not limited to the specific number of tines illustrated.

- The reciprocable cylinder is provided with a ported connection 18 in the head 11 and a ported connection 19 in the base 12 through which fluid pressure is admitted to and fluid exhausted from the cylinder, by means -of the control valve mechanism generally indicated by the numeral37, whichvalve mechanism is operated by the operator of the machine in association with which the grapple is used. The piston rod, as previously indicated, extends through the head 11, the upper extension being indicated by the numeral 14a and through the cylinder base 12. Packing glands 20, 21 are provided in the head and base to prevent the escape of fluid pressure from the cylinder. The piston rod 14 extends above and below the piston 13 a distance sufiicient to allow the cylinder to make a complete stroke relative to the piston and leave the upper and lower ends 14a, 14b entirely outside the head and base.

The cylinder base 12 projects laterally beyond the cylinder wall and is provided with six radially projecting brackets 22, which are equally spaced around the perimeter of the base. The spider is formed with six radially projecting brackets 24 equally spaced around the perimeter of the spider so that they will be in vertical alignment with the brackets 22. As illustrated in the drawings, each tine is formed with a rib 38 which has the end adjacent the spider pivotally connected" to one of the brackets 24 by a hinge bolt 25. Each tine is connected to the base 12 by means of one of the connecting links 17, one end of the rod being connected to one of the brackets 22 by means of pivot bolt 23 while the other end is connected to a rib 38 of a tine directly below it by means of the pivot bolt 26. Each pivot bolt 26 is connected to a rib 38 outwardly from the hinge bolt 25 at a point so that the links 17 will apply adequate force to close the tines around the material to be picked up.

The spider is universally mounted on the lower end of the piston rod by means of a universal joint consisting of a yoke 27 mounted centrally within the spider, as shown, by means of a pair of diametrically opposite trunnions 28, 29 which are journalled in the spider by means of trunnion blocks 30, 31 mounted in the spider diametrically opposite each other, trunnions being secured against displacement by means of set screws 32 and 33.

The central portion of the yoke 27 is formed hollow and the lower end of'the rod 14. is shaped so as to fit into the same, the yoke being pivotally mounted on the lower end 14b of the piston rod by means of a pivot pin 34 which passes through the yoke 32 and through the lower end of the rod 14 at right angles to the trunnions 28, 29. By this construction the spider can freely rotate on the lower end of the piston rod permitting it to have rotative movement as required when the grapple is picking up a load of material.

The grapple is raised and lowered when in use by a hoisting cable of the hoisting apparatus (not shown) one.

end of the cable being attached, as at 36 (FIG. 2)., tov the upper end 14a of the piston rod 14.

The operation of the grapple is as follows. FIGURE 2 shows the grapple open, in which position it is ready to pick up a load ofmaterial. In that position, the grapple is standing on the points of the tines and is safely supported by the cable against toppling over. No slack is necessary during the picking up operation. The operator then opens the fluid control valves so that fluid pressure is directed into the cylinder through the ported connection 19 and any fluid above the piston 13 will escape through the ported connection 13, which fluid pressure wil cause the cylinder to move downardly relative to the piston. The downward cylinder movement is translated to the tines so that they are caused to close. In addition to closing the grapple, the downward movement of the cylinder automatically allows for a general downward movement of the tines, thus allowing the grapple to dig into the loose material and pick up a full load. During this operation, the operator does not slacken the cable since the cylinder automatically lowers the tines relative to the material being. loaded. Consequently there is no danger of the grapple toppling over during the picking up operation.

In the event that solid material, such as hard chunks of ore or other material, becomes lodged between the tines during the picking up operation and thus prevent the uniform closing of the tines of the grapple, the universal mounting of the spider on the end of the piston rod hereinbefore described, will automatically compensate for that condition, allowing the spider to tilt in the direction required to permit the other tines to close without causing undue strain on the lower end of the piston rod.

While there is in this. application specifically described one form which the invention may assume in-practice, it will be understood that this form of the same'is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims. I

What we claim as new and desireto secure by Letters Patent is:

1. A fluid operated grapple adapted to be suspended on a hoisting cable and supported thereby during its entire operation and having a vertical reciprocable fluid cylinder, a piston contained in said cylinder, said piston normally remaining relatively stationary with respect to said cylinder and having a piston rod extending in opposite directions through the opposite ends of said cylinder a distance equal at least to the stroke of said cylinder relative to said piston, meansconnected to the upper end of said piston rod above the cylinder for attaching the cable thereto whereby the grapple is suspended from the cable, a spider mounted on the lower end of the piston rod, a plurality of tines pivotally mounted on said spider, links pivotally connected to said tines respectively and to said cylinder, and means for supplying pressure fluid to said cylinder to effect reciprocation thereof relative to said piston whereby during loading and dumping the tines are respectively closed and opened to load material into said grapple and to dump material therefrom by the reciprocation of said cyhnder, the downward stroke of said cylinder eilecting closing of said tines and simultaneously allowing the grapple to lower or fall a corresponding distance upon slackening of the cable, the grapple being firmly supported in an upright position by said cable during the operation of loading and dumping the same, said grapple having means for pivotally mounting said spider on the lower end of said relatively stationary piston rod for universal pivotal movement to prevent undue binding between the parts.

2. A grapple as set forth in claim 1 wherein said pivotal mounting means comprises a yoke pivotally mounted on said spider and coaxial therewith, and a member at right angles to the first mentioned yoke pivot mounting, pivotally mounting said yoke on the lower end of said relatively stationary piston rod.

3. A grapple as set forth in claim 1 wherein said pivotal mounting means for the spider comprises a yoke pivotally mounted on said spider and a pivot pin pivotally mounting said yoke .on the lower end of said relatively stationary piston rod, said pin being disposed at right angles to the yoke pivot mounting which pivotally mounts the yoke on the spider.

References Citedin the tile of this patent UNITEDSTATES PATENTS Rayburn July 19, 

